diff --git a/parser/README.md b/parser/README.md
index da2e038..dc2dbe6 100644
--- a/parser/README.md
+++ b/parser/README.md
@@ -37,16 +37,21 @@ Functions:
 | `cosh` | $\cosh(x)$ |
 | `cot` | $\cot(x)$ |
 | `exp` | $\exp(x)$ |
+| `inf` | $\inf(X)$ |
 | `lg` | $\lg(x)$ |
 | `ln` | $\ln(x)$ |
 | `log10` | $\log_{10}(x)$ |
 | `log2` | $\log_2(x)$ |
+| `max` | $\sup(X)$ |
+| `min` | $\inf(X)$ |
 | `prod` | $\displaystyle \prod_{i=0}^n x_i$ |
 | `sgn` | $sgn(x)$ |
+| `sign` | $sgn(x)$ |
 | `sin` | $\sin(x)$ |
 | `sinh` | $\sinh(x)$ |
 | `sqrt` | $\sqrt{x}$ |
 | `sum` | $\displaystyle\sum_{i=0}^n x_i$ |
+| `sup` | $\sup(X)$ |
 | `tan` | $\tan(x)$ |
 | `tanh` | $\tanh(x)$ |
 
@@ -58,6 +63,6 @@ Floating points: `.`, `,`
 
 Functions have only one argument, provided in braces. Operators must have two operands except minus (if it is the first character of equation or braced expression).
 
-`avg`, `sum` and `prod` applied on `numpy.ndarray` produce `float`.
+`avg`, `sum`, `max`, `sup`, `min`, `inf` and `prod` applied on `numpy.ndarray` produce `float`.
 
 **! There is no error handling yet !**
diff --git a/parser/parser/operation.py b/parser/parser/operation.py
index 7ff47cd..b6fb0e9 100644
--- a/parser/parser/operation.py
+++ b/parser/parser/operation.py
@@ -26,18 +26,23 @@ functions: dict[str, FunctionType] = {
     "cosh": np.cosh,
     "cot": cot,
     "exp": np.exp,
+    "inf": np.inf,
     "lg": np.log10,
     "ln": np.log,
     "log10": np.log10,
     "log2": np.log2,
+    "max": np.max,
+    "min": np.min,
     "prod": np.prod,
     "sgn": np.sign,
+    "sign": np.sign,
     "sin": np.sin,
     "sinh": np.sinh,
     "sqrt": np.sqrt,
     "sum": np.sum,
-    "tan": np.tan,
+    "sup": np.max,
     "tah": np.tanh,
+    "tan": np.tan,
 }
 
 operators: dict[str, OperatorType] = {